Speaker cables - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

Jac · 25th Sep 2018, 7:52 am

Quote:

Originally Posted by wd40addict

It's always surprised me that no-one has used a four way speaker cable to extend the amplifier's feedback loop right onto the loudspeaker terminals. This would remove the cable's contribution to reduced damping factor and should eliminate any influence of cable on sound.

I guess anyone who did this wouldn't be very popular in the high mark-up world of HiFi cables!

Kenwood did that with a.o. the L-02A and L-08M amplifiers.

Jac

Radio Wrangler · 25th Sep 2018, 9:54 am

Expensive speaker cables sell into the high end market, and the people there are highly averse to feedback. So making feedback more overt isn't going to go down well with the target market.

It's a common technique with high performance lab power supplies. The usually have a couople of 10 Ohm resistors from the main outputs to the feedback terminals in case someone forgets to connect something.

David

rontech · 28th Sep 2018, 6:57 pm

Quote:

Originally Posted by Linnovice

No offence intended, I’m just practising my ‘Albert’s stick with the horse’s head handle’ game. (Now hands up all those who remember that one, especially with Stanley Holloway.)

I used to have the Columbia 78 ( 12" I think ) of Albert & The Lion.

mark_in_manc · 28th Sep 2018, 7:19 pm

Quote:

Originally Posted by Radio Wrangler

[Feedback loop out to the load is] a common technique with high performance lab power supplies. The usually have a couple of 10 Ohm resistors from the main outputs to the feedback terminals in case someone forgets to connect something.

Farnell L30-E doesn't have such resistors - which is why mine was in the skip, as the default wire links between o/p and feedback terminals had dropped out. Less happily it took a couple of pages of thread on here for me to twig that fact

Radio Wrangler · 28th Sep 2018, 7:58 pm

On the ones with the resistors, the sorts of users who would lose the links also mistakenly would connect their load to the feedback terminals, not the proper output ones, thereby quickly burning out those resistors.

Doesn't matter how you try to engineer it, a good fool will always find a way round it!

David

sp10mk11 · 29th Sep 2018, 11:04 am

A cheap experiment is 1.5mm solid core lighting cable, this always works well I have found.

Gary

AC/HL · 29th Sep 2018, 4:43 pm

Five posts split to a new thread: https://www.vintage-radio.net/forum/...d.php?t=150130

G4YVM David · 1st Oct 2018, 7:55 am

Talk of audiophools and proper speaker wire ...i saw this earlier. Im not quite sure what to make of it, but audiophool does come to mind. Having said that I recall clearly, in c 1980, listening to good mini phones (remembet the teeny foam padded ones we invented ti go with walkmans etc? Now kids have gone back to speakers strapped to their heads...why did we bother?). Anyway, they blew my mind so maybe these cans are worth it. But I doubt it.

David
https://www.head-fi.org/showcase/sta....13431/reviews

Radio Wrangler · 1st Oct 2018, 8:34 am

Ah, now the round Stax headphones are genuinely superb. The prices are extreme, far too high for what they're made of, I suspect, but they are the real deal.

These are most definitely not audiophile fluff.

They need a power amp to drive them, so they won't work from normal headphone jacks. Stax try to flog you their own very expensive valve-based driver box, but the earlier ones used a step-up transformer.

The audiophile interest kicks in, I assume, because they are in the conspicuous consumption price bracket.

The reviews you found are phoolery "I would have reviewed them totally differently if the system they were in used less good interconnects than....." and words to that effect.
Ignore the reviews. If you ever get a chance to try a pair of Stax phones, take it. You'll be surprised.

A friend has had a pair since the early seventies. They were pricy then but not out of reach and the adaptor box was the transformer type.

David

Craig Sawyers · 1st Oct 2018, 10:06 am

Totally agree about STAX, although the most recent ones seem to have reliability problems after they went across to using a different diaphragm material. I have two pairs of STAX phones (a 1980's Lambda and an SR-007II), and three valved energisers that I built myself to designs by Kevin Gilmore, one of them a replica (electrically) to the legendary SRM-T2, but with decent thermal management and a regulated power supply. The only wiring that needs care are the power umbilicals from the supply to the amp, since they are at various voltages up to 600V - so need high voltage rated ptfe sleeved wires.

https://www.head-fi.org/threads/stax...r-made.847212/

But I also have an old pair of KOSS ESP-9 that I picked up off eBay for not much. They needed some TLC because the foam damping in the cups had turned to gooey tar. And the fluid-filled earcups were empty, and replaced with aftermarket ones. After much cleaning and replacement with loudspeaker wadding they fired up straight away. But, although head crushingly heavy, they sound great. The energiser is a complete nightmare however - a rats nest of wiring that must have given Koss's production department a real headache to build.

A more budget (as compared with STAX that is!), but excellent, option is the current KOSS ESP-950. Although it seems it is most commonly available only in the US (why?) it is $999 including the energiser. Plus shipping, tax etc etc - which in practice means it will be around £900.

https://www.koss.com/headphones/over...dphones/esp950

Craig

Radio Wrangler · 1st Oct 2018, 10:47 am

Oh, I bought a pair of the little Sony MDR7 phones back in the eighties.

I had them in the lab at HP when I was setting my Revox A77 back up after replacing its heads. The phones were left lying across it when I went for lunch. When I returned, some wag had made and attached a paper label to the Revox Panel "Sony Staggerman"

So I now have for life the image of a runner with small headphones lugging an A77!

David

Ted Kendall · 1st Oct 2018, 11:10 am

Confession time - I bought a pair of SR-5s plus the transformer unit in Notting Hill Gate some time in the eighties for a cough and a spit. Didn't actually fire them up for twenty years - don't ask me why. They worked well, but had a slight tizz on one side on peaks. Some searching found a pair of SR3/IIs and, shortly after, a spare set of SR5 earpieces plus cable from the States - NOS. Who's a lucky boy, then? Can't tell much difference between the 5 and the 3/II.

A surprisingly close substitute is the original Wharfedale Isodynamic, which also needs to see a speaker output. The pleather earpads will be shedding by now, but they ain't half bad!

Radio Wrangler · 1st Oct 2018, 1:18 pm

I had a pair of Isodynamics and they were very good. Sadly they got binned when the earpads turned to tar. Sounded very good indeed.

David

PJL · 1st Oct 2018, 1:37 pm

I have a pair of wharfedale Isodynamics bought new in the 70's. The plastic 'skin' peeled off the earpads but underneath is a material finish that looks perfectly OK They are still perfectly usable.

25th Sep 2018, 9:54 am	#42
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Speaker cables Expensive speaker cables sell into the high end market, and the people there are highly averse to feedback. So making feedback more overt isn't going to go down well with the target market. It's a common technique with high performance lab power supplies. The usually have a couople of 10 Ohm resistors from the main outputs to the feedback terminals in case someone forgets to connect something. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

28th Sep 2018, 7:58 pm	#45
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Speaker cables On the ones with the resistors, the sorts of users who would lose the links also mistakenly would connect their load to the feedback terminals, not the proper output ones, thereby quickly burning out those resistors. Doesn't matter how you try to engineer it, a good fool will always find a way round it! David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

29th Sep 2018, 11:04 am	#46
sp10mk11 Octode Join Date: Feb 2009 Location: Cornwall, UK. Posts: 1,275	Re: Speaker cables A cheap experiment is 1.5mm solid core lighting cable, this always works well I have found. Gary

29th Sep 2018, 4:43 pm	#47
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: Speaker cables Five posts split to a new thread: https://www.vintage-radio.net/forum/...d.php?t=150130

1st Oct 2018, 7:55 am	#48
G4YVM David Heptode Join Date: May 2014 Location: Salisbury, Wiltshire, UK. Posts: 998	Re: Speaker cables Talk of audiophools and proper speaker wire ...i saw this earlier. Im not quite sure what to make of it, but audiophool does come to mind. Having said that I recall clearly, in c 1980, listening to good mini phones (remembet the teeny foam padded ones we invented ti go with walkmans etc? Now kids have gone back to speakers strapped to their heads...why did we bother?). Anyway, they blew my mind so maybe these cans are worth it. But I doubt it. David https://www.head-fi.org/showcase/sta....13431/reviews

1st Oct 2018, 8:34 am	#49
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Speaker cables Ah, now the round Stax headphones are genuinely superb. The prices are extreme, far too high for what they're made of, I suspect, but they are the real deal. These are most definitely not audiophile fluff. They need a power amp to drive them, so they won't work from normal headphone jacks. Stax try to flog you their own very expensive valve-based driver box, but the earlier ones used a step-up transformer. The audiophile interest kicks in, I assume, because they are in the conspicuous consumption price bracket. The reviews you found are phoolery "I would have reviewed them totally differently if the system they were in used less good interconnects than....." and words to that effect. Ignore the reviews. If you ever get a chance to try a pair of Stax phones, take it. You'll be surprised. A friend has had a pair since the early seventies. They were pricy then but not out of reach and the adaptor box was the transformer type. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

1st Oct 2018, 10:06 am	#50
Craig Sawyers Dekatron Join Date: Nov 2010 Location: Oxford, UK. Posts: 4,996	Re: Speaker cables Totally agree about STAX, although the most recent ones seem to have reliability problems after they went across to using a different diaphragm material. I have two pairs of STAX phones (a 1980's Lambda and an SR-007II), and three valved energisers that I built myself to designs by Kevin Gilmore, one of them a replica (electrically) to the legendary SRM-T2, but with decent thermal management and a regulated power supply. The only wiring that needs care are the power umbilicals from the supply to the amp, since they are at various voltages up to 600V - so need high voltage rated ptfe sleeved wires. https://www.head-fi.org/threads/stax...r-made.847212/ But I also have an old pair of KOSS ESP-9 that I picked up off eBay for not much. They needed some TLC because the foam damping in the cups had turned to gooey tar. And the fluid-filled earcups were empty, and replaced with aftermarket ones. After much cleaning and replacement with loudspeaker wadding they fired up straight away. But, although head crushingly heavy, they sound great. The energiser is a complete nightmare however - a rats nest of wiring that must have given Koss's production department a real headache to build. A more budget (as compared with STAX that is!), but excellent, option is the current KOSS ESP-950. Although it seems it is most commonly available only in the US (why?) it is $999 including the energiser. Plus shipping, tax etc etc - which in practice means it will be around £900. https://www.koss.com/headphones/over...dphones/esp950 Craig

1st Oct 2018, 10:47 am	#51
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Speaker cables Oh, I bought a pair of the little Sony MDR7 phones back in the eighties. I had them in the lab at HP when I was setting my Revox A77 back up after replacing its heads. The phones were left lying across it when I went for lunch. When I returned, some wag had made and attached a paper label to the Revox Panel "Sony Staggerman" So I now have for life the image of a runner with small headphones lugging an A77! David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

1st Oct 2018, 11:10 am	#52
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,675	Re: Speaker cables Confession time - I bought a pair of SR-5s plus the transformer unit in Notting Hill Gate some time in the eighties for a cough and a spit. Didn't actually fire them up for twenty years - don't ask me why. They worked well, but had a slight tizz on one side on peaks. Some searching found a pair of SR3/IIs and, shortly after, a spare set of SR5 earpieces plus cable from the States - NOS. Who's a lucky boy, then? Can't tell much difference between the 5 and the 3/II. A surprisingly close substitute is the original Wharfedale Isodynamic, which also needs to see a speaker output. The pleather earpads will be shedding by now, but they ain't half bad!

1st Oct 2018, 1:18 pm	#53
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,902	Re: Speaker cables I had a pair of Isodynamics and they were very good. Sadly they got binned when the earpads turned to tar. Sounded very good indeed. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

1st Oct 2018, 1:37 pm	#54
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Speaker cables I have a pair of wharfedale Isodynamics bought new in the 70's. The plastic 'skin' peeled off the earpads but underneath is a material finish that looks perfectly OK They are still perfectly usable.